The impact of finite-amplitude bottom topography on internal wave generation in the Southern Ocean
Polzin, Kurt L.
MetadataShow full item record
KeywordCirculation/ Dynamics; Diapycnal mixing; Internal waves; Mixing; Mountain waves; Topographic effects; Waves, oceanic
Direct observations in the Southern Ocean report enhanced internal wave activity and turbulence in a kilometer-thick layer above rough bottom topography collocated with the deep-reaching fronts of the Antarctic Circumpolar Current. Linear theory, corrected for finite-amplitude topography based on idealized, two-dimensional numerical simulations, has been recently used to estimate the global distribution of internal wave generation by oceanic currents and eddies. The global estimate shows that the topographic wave generation is a significant sink of energy for geostrophic flows and a source of energy for turbulent mixing in the deep ocean. However, comparison with recent observations from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean shows that the linear theory predictions and idealized two-dimensional simulations grossly overestimate the observed levels of turbulent energy dissipation. This study presents two- and three-dimensional, realistic topography simulations of internal lee-wave generation from a steady flow interacting with topography with parameters typical of Drake Passage. The results demonstrate that internal wave generation at three-dimensional, finite bottom topography is reduced compared to the two-dimensional case. The reduction is primarily associated with finite-amplitude bottom topography effects that suppress vertical motions and thus reduce the amplitude of the internal waves radiated from topography. The implication of these results for the global lee-wave generation is discussed.
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 44 (2014): 2938–2950, doi:10.1175/JPO-D-13-0201.1.
Showing items related by title, author, creator and subject.
Hendry, Ross MacRae (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1975-04)This thesis reports on an investigation into the structure, energetics and propagation of tidal frequency internal waves. Data from Site D, near the New England continental slope, Muir Seamount northeast of Bermuda, and ...
Xu, Jinshan (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)This thesis covers a comprehensive analysis of long-range, deep-ocean, low-frequency, sound propagation experimental results obtained from the North Pacific Ocean. The statistics of acoustic fields after propagation ...
Unknown author (Ocean Carbon & Biogeochemistry (OCB) Program and International Ocean Carbon Coordination Project (IOCCP), 2013-11)Ocean time-series represent one of the most valuable tools scientists have to characterize and quantify ocean carbon fluxes and biogeochemical processes and their links to changing climate. In order to acquire a more ...